>>>>> "M" == Massimiliano Mirra <list / chromatic-harp.com> writes: M> if method_name =~ /^#{@solve_prefix}/ M> variable_name = method_name.gsub(@solve_prefix, "") You don't need the #gsub, write it M> solve_for(variable_name) solve_for($') M> else M> The one thing I would have liked to do but have not been able to, was M> of using :symbol's instead of strings as keys for the @formulas hash. M> The difficulty arose in method_missing when trying to get the :symbol M> from the variable (didn't find anything that looks like M> "a".to_symbol). String#intern pigeon% ruby -e 'p "a".intern' :a pigeon% Guy Decoux